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Article type: Cover
1981Volume 300 Pages
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Published: February 28, 1981
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Article type: Cover
1981Volume 300 Pages
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Published: February 28, 1981
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Article type: Index
1981Volume 300 Pages
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Published: February 28, 1981
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Article type: Appendix
1981Volume 300 Pages
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Published: February 28, 1981
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JUN SAKAMOTO, YOSHIRO KOHAMA, TAIJI TANABASHI, TETSUYA KATAYAMA
Article type: Article
1981Volume 300 Pages
1-9
Published: February 28, 1981
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In the preceding paper [I], a hypothesis of accumulation law and stochastic equations for randomly accumulated plastic deformations are presented and also, analytical methods are described. Analytical examples of random accumulations in Steel and Steel Reinforced Concrete members under random curvature amplitudes are shown and based on the numerical results with Monte-Carlo simulations, random damages are discussed in this paper.
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TSUNEYOSHI NAKAMURA, SHUICHI KAMAGATA, IKUO KOSAKA
Article type: Article
1981Volume 300 Pages
11-18
Published: February 28, 1981
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A complete set of uniaxial constitutive relations has been formulated on the basis of the non-stationary hysteretic uniaxial stress-strain relations in Ref. [6] and [8] due to the senior author. While Ref. [6] has provided empirical formulae for determining the parameters in a Ramberg-Osgood representation of a smooth piece of stress-strain curves, some postulates and tentative assumptions have to be introduced for applications of the formulae to various possible series of successive path pieces. In order to provide a complete transition law from one smooth path piece to the next, a detailed classification of path patterns has been made and necessary ingredients of a computer subroutine of the constitutive law have been clarified. A brief explanation has been included of a method of generating incremental member stiffness matrices to be incorporated in a computer program for frame analysis.
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JUNJI MAEDA, MINORU MAKINO
Article type: Article
1981Volume 300 Pages
19-29
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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Three methods are well known for estimation of spectral densities of descrete time series; Blackman-Tukey, Cooley-Tukey (FFT) and auto-regressive model (AR) methods. The fundamental properties of FFT and AR methods are reviewed for the methods of spectral analyses of turbulent winds since Blackman-Tukey method is equivalent to Cooley-Tukey method in the viewpoint of statistical errors of estimates. In this paper it is shown that the choices of record length and sampling frequencies by using the scale of turbulence and the nondimensional frequencies are very useful. Comparisons of these two methods are illustrated by numerical examples on observed data. FFT method has a few demerits which are not sufficiently refined by averaging and/or window operations, while AR method is preferable for estimating spectral densities of turbulent winds though these statistical errors are not defined.
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HIROMASA KAWAI, HATSUO ISHIZAKI
Article type: Article
1981Volume 300 Pages
31-39
Published: February 28, 1981
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Characteristics of pressure fluctuations on the windward wall of square prisms were investigated by the wind tunnel tests and compared with the results of the theory proposed by J. C. R. Hunt. From the experiments, we found the follcwing results. (1) The power sprectra of the pressure fluctuations on the windward face decayed more rapidly in the high frequency range than that of the free stream turbulence. The rate of the spectral decay of the pressure fluctuations was from -3 at the middle point to -5/3 at the edge point. (2) The scales of the pressure fluctuations were increasing with the ratio of the size of the prism to the turbulence scale, B/L_x. At B/L_x=1.47, the scales were about 1.5 times and 2.0 times larger than those of the free stream turbulence in vertical and horizontal directions respectively. (3) The results of the Hunt's theory which was a generalization of the rapid distortion theory, were qualitatively agreed well with the results of our experiments. However, there were some points shown the quantitative difference between the theory and the experiment. The ratio of the spectral decay of the theory in the high frequency range was much greater than that of the experiments. (4) The linear transformer of the upstream velocity fluctuation to the pressure fluctuation which was named "pressure/velocity admittance" by the authors, was a function of only the reduced frequency n・B/U for any scale and intensity of turbulence, and expressed by the following equation [numerical formula] where |x_<up>|^2 is the pressure/velocity admittance, a is the decay parameter which changes from point to point. At the middle point, α=2/3 for any scale and intensity of turbulence. (5) The gust factors of the tall building based on the experimental results were about 15%〜20% higher than those of the method of A. G. Davenport assuming the vertical and horizontal co-spectra were expressed by exp (-C_vn⊿z/U_z) and exp (-C_H・n・⊿y/U_z) where C_v=8 and C_H=20 respectively. They were as same as those of the same method assuming C_v=C_H=8.
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SEIJI YOSHIZAKI, YOSHIKAZU KANOH
Article type: Article
1981Volume 300 Pages
41-48
Published: February 28, 1981
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ACI method for predicting the strength of slab-column connections that transfer shear and moment is based on a linear variation in shear stress. Calculated values by this method are conservative when compared to measured strengths. That conservatism is due to an underestimation of the moment which is transferred between the slab and the column by torsion. Torsion tests of slab-column connections were carried out to directly investigate the magnitude of the moment that can be transferred by torsion. Based on the test results, cracking patterns, failure mode, relationship between torsional moment and angle of rotation, ultimate strength, etc. are described with figures and tables in this paper. Consequently, it is proved that the moment which can be transferred between the slab and the column by torsion, when converted into a torsional shear stress by full plastic formula, equals about 100kgf/(cm)^2 and is far greater than the value assumed in the ACI method. A method for predicting the strength of slab-column connections transferring shear and moment is suggested.
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HOKATO EGAMI
Article type: Article
1981Volume 300 Pages
49-55
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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The rigidity of joints has a powewful effect on the stress distribution in the plane structures composed of the precast reinforced concrete panels. For that reason, it is desired that we compute the stress distribution in the plane structures by establishing the method of structural analysis on the precast reinforced concrete panel structures and establish a seismic analysis of that. In this paper, it was ascertained that we could find out the magnitude of the rigidity of joints by experimental studies on the joint in the precast reinforced concrete panel structures composed of two panels and could adopt these values on this analysis. For this reason, the methods which replace the panel joints in the plane structure with the other kind members and adopt the value of the rigidity of these members, obtained by the exparimental study on the joints, were developed under axial forces. As compared the theoritical results obtained by this method with experimental results, it was obtained that both propriety and utility of this method were confirmed. Then we calculated both stress distribution along the panel edges and deformation of the panels in a precast reinforced concrete panel wall, subjected to the action of the seismic force. We can forecast the process of the behaviour of these structures subjected to axial forces by adopting the value of joint rigidity, changing momentarily according to the action of the forces. This method may be adopted for representing the stress distribution in the plane structures composed of the precast reinforced concrete panels subjected to the earthquake loads and further may be useful for establishing the seismic design of the precast reinforced concrete panel structures.
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TAKESHI USHIYAMA, YOSHIZO DOBASHI
Article type: Article
1981Volume 300 Pages
57-65
Published: February 28, 1981
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In the previous part one of this report, prior to the discussion on the structural design of staircases of folded slabs or helicoidal shells results of analysis of elasto-plasthic behaviors of various types of reinforced concrete staircases were compared with their test results, so that the relation between their elastic limit and ultimate strength was clarified. Based on the above consequence, particularly herein for free-standing staircases in case of different angles between the horizontal projections of centerlines of their pair of flights finite element solution is obtained in an attempt to examine their mechanical characteristics, and thereupon a method of their structral desigh is proposed.
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TAKUJI KOBORI, KOICHIRO ASANO
Article type: Article
1981Volume 300 Pages
67-72
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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Here is presented a new analytical technique for the response analysis of soil-hysteretic structural systems subjected to earthquake-like white base motions. This technique was developed by making use of the "Dynamical Ground Compliance" concerning the rectangular foundation resting on the elastic-half space and the markov-vector approach concerning the random response analysis of hysteretic systems. Some computational results showed that this technique was sufficiently applicable to the problem of soil-structural systems with severe non-linearity. From comparative discussions on computational results, it was found that soil-structure interaction had favorable effects on the responses of hysteretic systems which had relatively weaker nonlinearity due to the increasing dispersive damping accompanied by the softening stiffnes phenomenon of soils, while it had rather unfavorable effects on those which had relatively stronger nonlinearity due to the amplifing selective chracteristics of the systems on the lower frequency portions of the energy of earthquake excitations. This tendency became more pronounced with the longer duration and higher amplitude level of random earthquake excitations.
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KATSUYOSHI YAMABE
Article type: Article
1981Volume 300 Pages
73-82
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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This paper discusses more quantitatively by means of various aspects on the first natural periods and damping coefficients obtained by vibration test, microtremors observations and seismic observations in actual buildings. Some of the significent aspects of the results of this paper are summarized as follows : 1) The experimental values are smaller than structural design values, the average rate of those values of SRC and S buildings are 60% and 80%, respectively. The seismic values are larger than the experimental values, the average rate of those values are about 20% against medium earthquake (70〜110 gal). 2) In the San Fernando Earthquake, the relation between the maximum acceleration on the top floor and the first natural periods (T_B) or the predominant periods (T_P) during the earthquake are obtained as follows, respectively : α_<mzx>=2.0×10^2T^<-0.45>_B…(7), α_<mzx>=2.4×10^2T^<-0.37>_B…(8) 3) The values of the predominant periods and first damping coefficients of actual buildings show a tendency to increase with the acceleration of the earthquake motion. 4) The empirical formura concerning the first natural periods of actual SRC and RC buildings are obtained as follows, respectively : SRC buildings : T(sec)=0.058N_1…(5) RC buildings : T(sec)=0.073(N+03N_0)…(6) in which N_1, N and N_0 represent number of stories of main structure part, above the G. L. and underground part, respectively.
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SUKENOBU TANI, SETSURO NOMURA, TOMOYA NAGASAKA, AKIRA HIRAMATSU
Article type: Article
1981Volume 300 Pages
83-94
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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The main purpose of this paper is to establish a hysteresis model that can predict the force-deformation characteristics for wide deformation region as realistically as possible. To begin with, restoring force characteristics is examined based on the results of several experiments of reinforced concrete aseismatic elements, such as one bay portal frames, frames with diagonal bracings and frames with shear wall. As a result of this examination, we can find some interesting remarks as follows that Normalized Characteristic Loops can be established even in large deformation region. And also, in case of non-symmetric hysteresis loops as well as in case of symmetric loops, we can derive Normalized Characteristics Loops that are inherent in each aseismatic element individually. In large deformation region, deterioration phenomina due to alternately reversible loadings are observed quite remarkably on various aspects. Two of these aspects, i. e. stiffness degradation and strength degradation, are investigated. However, the other aspects cannot be investigated due to insufficient data. Subsequently, a mathematical model which represents force-deformation relationship for wide deformation region extending from beginning up to the state of ultimate collapseis decribed. This model is developed by improving so called NCL model that should represent hysteretic behaviour at any stage by connecting the Skeleton Curve with the Normalized Characteristic Loop. And this improved model can represent the phenomenon of degradation in rather simple manner. Lastly, brief comparisons of the experimental results with calculated results are made. And a satisfactory result is obtained.
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MASAYUKI MIZUHATA
Article type: Article
1981Volume 300 Pages
95-104
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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Process of the movement of the internal condensation front when the condensation and reevaporation take place in a homogeneous structure is a kind of the moving boundary problems. In the problems of solving the moisture transfer equations expressing the process, the finite-difference representation of derivatives of vapor pressure and water content with respect to the space variable at the nodal points near the condensation front requires special consideration because the condensation front is moving. In this paper the moisture transfer equations are represented by the finite-difference applying such a consideration that is given in a method of the numerical solution for the non-steady state heat conduction problems involving melting of ice, and the solutions by the use of the equations deciding the water vapor pressure, water content and the place of condensation front within materials were derived. Using these solutions, the movement of the condensation front in flat roofs made of cellular concrete with a vaporproof layer on the cold side is calculated under conditions which the temperature and the hnmidity are constant on both indoor and outdoor sides. The results above are compared with the ones obtained by a simple method under the same conditions. Water Content distributions within condensation layer are also calculated in the case of taking account of the decrease of the thermal conductivity due to the internal condensation in materials.
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TOMOHIKO KOMADA
Article type: Article
1981Volume 300 Pages
105-113
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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This study is one attempt of developing a system of preferred modular sizes in building. For the practical means to control the decentralized development of the previous series like a development of the EPA numbers or doubling series, this system choices the sexagenary one and deals with numbers arranged in theoretical orders in a limited system mingling with the decimal system. The reason to choice the number 60 of the sexagenary are : 1. The boundary number is to be larger than number 40 of the Renard Series R 40 which is used in engineering science, for the complexity of the building industry, but to be not so large as 90. 2. The number should have more divisors as much as possible for the flexibility. This sexagenary system allows to get the secondary or tertiary numbers, for example 84 or 180 like a calling of clock's number, for example 14 o'clock or 20 o'clock, and allows also in this case for multiplication of all sizes by 10 like the present Japanese System to an increased series of modular sizes. For the Systematic presentation of 60 numbers limimed in sexagenary, the arrangement is developed on the torus, of which the character is to have many rings and spiral rings on the surface which may allow the continuity of the numerical circulativity like the clock system. (Fig. 27, 29, 31) The principal series on the torus have respectively the increment of 2, 3 or 5, which are three primary themes for the practical purpose and have also the Fibonacci's character. And then the series having increment of 6 can be found easily. This numerical arrangement of the sexagenary system on the torus has many mutual numerical relations among adjacent numbers (Fig. 11, 12) and has many arithmetical series which are more useful than progressive for the system of preference for numbers for use as the numerical factor in multimodular sizes for vertical and horizontal dimensions in building. This study may expect to make a start point for revising JIS A 0001 Architectural Module in Japan for the practical purpose.
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HIROYASU FUJIOKA
Article type: Article
1981Volume 300 Pages
115-123
Published: February 28, 1981
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This paper shows the changes of the exterior design of Tokyo municipal elementary school buildings built of reinforced concrete and points out that pursuit of clarity, rather than that of rationalism, is shown in the simple exterior design after 1931 which is characterized by whitish smooth surface with only rectangular windows.
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JUICHIRO NARITA
Article type: Article
1981Volume 300 Pages
125-132
Published: February 28, 1981
Released on J-STAGE: August 22, 2017
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We studied on the quality and amount and method of rough cutting of wood that made material of ONE MILLION MINIATURE PAGODA. I made many PAGODAS as the trial manufacture by trial manufactured face lathe, and studied the detail of engineering trouble. Then we conjectured the number of oprated face lathe per day by the time needed for making up one PAGODA.
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SEIROKU OTA
Article type: Article
1981Volume 300 Pages
133-139
Published: February 28, 1981
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I proved that the stone arch bridge construction was first introduced into Japan from china.
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Fukujiro FURUMURA, Yasuji SHINOHARA
Article type: Article
1981Volume 300 Pages
141-149
Published: February 28, 1981
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In the past, the authors studied the fire resistance of protected steel columns in fire. In this study, the inelastic behaviors of protected steel beams and frames that are exposed to a thermal history similar to that obtained in a standard furnace fire test are investigated numerically by the method of finite element elasto-plastic-creep analysis, including thermal and mechanical properties of steel under high temperatures and geometrical nonlinearities of steel members.
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